Preparation and characterization of TiO2 thin films grown by RF magnetron sputtering

Titanium dioxide (TiO2) thin films were obtained by RF sputtering technique. The samples were deposited on glass and p- silicon substrates at an argon flow rate of 4.9 sccm and at room temperature during 4 h. In this work, the influences of RF power density and annealing temperature on properties of obtained thin films were investigated. The morphological, structural and optical properties were studied by Atomic Force Microscope (AFM), X-ray Diffractometer and UV–VIS–NIR spectrophotometer respectively. A high transmission (about 80%) in the visible region, crystalline structure and a direct band gap (between 3.4 and 3.5 eV) were ob- served by the measurements. Thin films were annealed at different temperatures (from 300 to 500 °C) during 30 minutes in order to investigate the annealing effect on properties of TiO2 thin films. The refractive index and the roughness increase with increasing annealing temperature. The results of this work suggest that the properties of TiO2 thin films are sensitive to sputtering parameters. It is possible to obtain sputter-deposited TiO2 films at room temperature, without using reactive oxygen, with a good predominance of anatase (101) structure after the annealing at 400°C. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)